Alloy of iron.



Flo I;

JAMES MSEY SPEER, 0F TRAPPE, MARYLAND, AND WILLIAM L. IEOltS'TEIt, 0F

RUCHESTER, PENNSYLVANIA, ASSTGNORS T0 PITTSBURGH TRON dz STEEL FUUN- IDRIJES COMPANY, OF MIDLAND, TENN3YLVANIA, A CORPGRATIQN 01E PENNSYL- Patented Aug. 00, i013.

"MANILA.

ALLOY OF IRON.

Lqt'jji gfigt Specification of Letters Patent.

No Drawing.

the United States, residing at Trappe, in

the county of Talbot, State of Maryland, and at Rochester, in the county of Beaver, State of Pennsylvania, respectively, have invented new and useful Improvements in Alloys of Iron, of which the following is a specification.

Our invention relates to an alloy of iron known as adamite. The main constituents of our new alloy are iron, silicon, sulfur, phosphorus, manganese, carbon, nickel, and chromium, with or without small quantities of copper, tungsten, and other rare metals which do not materially affect the character of the alloy as hereinafter described.

Our alloy is especially remarkable in that its tensile strength closely approximates that of steel while it has characteristics of cast iron. Tests of bars of our alloy cut from an untreated casting have shown the In these transverse tests the breaking loads were applied at the center of the bars midway between their end supports, which were ten inches apart. The diameter of each bar was 1.245 inches.

Generically, our invention comprises castings containing the elements and the percentages thereof following: silicon 10% to 2.00%; chromium .5% to 1.50%; nickel 25% to 1.00%; sulfur below 05%; phos phorus below 12%; manganese 45% or less, and total carbon 1.25% to 3.50%. Such castings show remarkable results in tensile and transverse strength, and in wearing and abrasive qualities, and in resistance to the action of heat.

Hereinafter we give various analyses of castings which are specific embodiments of our generic invention, defined in the para graph next preceding this paragraph.

Analysis of samples of the bars herein-- epplication filed. March 18, 1913. Serial No. 755,162.

before referred to showed their composition to be as follows: silicon 370%, sulfur 033%, phosphorus 010%, manganese 25%, total cgig'gon 1.88%, nickel 50%, and chromium 0| We have found that in casting various sections the amount of silicon and carbon must be varied in accordance with general foundry practice to get the desired results; and it is for that reason that the maximum and minimum limits which we have given for silicon and total carbon are quite far apart. In fact, we would not limit ourselves to the amount of silicon and carbon mentioned herein in case the castings to be made should have a very enormous section. For example, the variation in the analyses depending on the size of the casting is best case of a casting 28 inches in diameter, the

analysis wasz-silicon, .60%; sulfur, 03%;

phosphorus, 043%; manganese, 30%; total carbon, 2.13%; nickel, .50%; chromium 1.05%. The result was a very hard resistant material, requiring the lowest lathe speed and the highest grade of tool steel to dress it.

In the case of a 1 inch or 2 inch tube mill plug, two analyses were as follows: silicon, 1.55%, 1.70%; sulfur, .023%, 023%; phosphorus, 096%, 096%; manganese, .45%, .45%; total carbon, 2.93%, 3.20%; nickel, .43%, .43%; chromium, 85%, 85%. The results obtained in these cases were materials which were hard and resistant to the action of abrasion under heat, and susceptible of being forged. Forging a steel of over 3% carbon is a feat hitherto unknown.

We have found that our alloy wears ten times longer than the best grade of cast iron obtainable forcomparison, and in a number of cases its wearing quality has shown even a greater degree of efiicieny. Our alloy has a remarkable resistance to abrasion under the action of heat. It has shown an efficiency of from five to ten times that of cast iron where constant wear under the action of heat was the characteristic considered.

'We do not deem it proper to designate our alloy adamite as either iron or steel, as these words are commonly known to the trade; we believe we'have made the discovcry of a new composition of metals, which,

I ing qualities class it with a steel product.

We have not found it feasible or possible to produce our alloy commercially in a cupola or like furnace. The pneumatic proc ess can be used but at great expense on ac-' count of re-carburizing to the extent that is necessary for our alloy. The crucible process may also be used, but its greater cost and smaller units of production make it an inconvenient and costly method of producing even such smaller weight castings of our alloy as the size of crucibles would permit. The air furnace may also be used for making our alloy, but the control of temperature and carbon and silicon in this type of furnace is diflicult and rather unsatisfactory for a uniform product. We have found that the regenerative open hearth furnace or 1 the electric furnace is best adapted for producing adamite In these furnaces the required control of the temperature at the time of melting and of pouring, which is essential, can be had, which is not possible in a cupola or like furnace. Also the constituent analyses as given for our alloy cannot be obtained from the cupola or like furnace in the case of castings of' larger section. In attempting to make our alloy in a cupola the percentages of silicon, sulfur and phosphorus we have found too high to get uniform results. We have found thatany such percentages of silicon,

sulfur and phosphorus as are contained in the metal, the tests of which were reported in the Iron Age, as above stated, would be destructive to the remarkable results which we have obtained and described herein. In

producing our alloy in a regenerative open erative open hearth furnaces or electric fur-' naces, in making up our charge of raw materials and as is well known in the art we may use steel scrap in our raw material charge, of the proper analyses to enable us to secure the proper proportion-ofcarbon, silicon. The same result, however, can be Y obtained by not using any scrap but working the carbon and silicon out of the charge with the addition of ore. After we have introduced our charge in the melting furand hardness.

na'ce, no chemical action of any considerable importance need necessarily take 'place provided our raw materials run close to the figured analyses; in other words, if the raw materials run close to the required analyses, our process is a melting one, the getting of sufiicient heat to enable usto pour the casting of the size required. If, however, our materials in the raw material charge do not run in analyses as figured, it may be necessary for us to hold a charge in the furnace a suflicient length of time to eliminate elements, as. silicon and carbon. which run higher than we have figured them. If the required elements are lower than the figured analyses, we add in the furnace what is lacking to give us metal of our alloy compositi0n,-as noted herein. It is understood that the usual loss in melting in furnaces is allowed for and taken care of in the ordinary manner. It is not necessary in all cases to add material which will produce a slag to reduce this oxidation, because a certain amount of slag will naturally be produced from the nature of the materials charged. We desire however, to cover any addition of material necessary to control oxidation. If our alloy is made in a regenerative open hearth furnace it may have either an acid or a basic lining as commonl known in the trade. However, our pre erence is for the acid-bottom furnace.

It has been claimed that iron castings containing nickel and chromium with a high total carbon content is of value. From our experience We do not attach any importance to the increased carbon contained in such castings, made with the combination of alloys similar to ours; at least, no such results can be obtained in tensile and transverse strengths as we have obtained in our alloy Where the control of the carbon is not complete in connection with the control of the silicon, depending upon the size and sections of the castings. It has also been claimed that manganese over 25% in steel metal mixtures containing nickel and chromium is most harmful where hardness and toughness are the special qualities required. From our experience we do not attach any importance to this claim for low manganese in a higher carbon alloy such as ours.- Our best results are obtained, as previously stated by a complete control of the carbon and silicon; the manganese varying in usual limits without any serious effect.

We have found in certain sections of our castings that it is necessary to anneal such castings to preserve their uniform strength In this feature our alloy strongly resembles steel. After the metal has been cast as "described, we have found that in castings of large section, if they are tumbled out of the molds as promptly as can be done without affecting their solidity, they.

have a tendency of self-hardening in the air. A similar method to this can be adopted for any class of castings where the wearing service is the essential feature. In the case of castings which are to be forged or dressed for use as tools, we refer to follow the practice of annealing rst, although this is not always essential, then forging and finishing them. and finally plunging them. into 'hot water or oil to secure the degree of hardness required. We have found that we can roduce an alloy of the two analyses given elow, which can be so treated. It can be forged into a lathe tool or drill and roperly annealed and hardened. The per ormance of these tools is the equal of the highest grade of crucible tool steel. The analysis of one sample was; silicon .7 0% sulfur 033%, hosphorus 040%, manganese 250%, carn 1.88% nickel .50%, chromium .90%. The analysis of "another sample was: silicon .60%, sulfur 033%, phosphorus 073%, manganese 22%, carbon 2.26%, nickel .53%, chromium .90%. The tensile strength of the first sample showed 91,220 lbs. per sq. in. without any change in area, elongation, or elastic limit other than would be observed in cast iron. The structure of such material after being forged is similar in every respect to the highest grade of tool steel made in a crucible furnace. The advantage of this method of producing our alloy is obvious for the reason that the manufacturin cost is considerably less than crucible stee and we are not depending in any .way upon any of the rarer and more expensive elements for our results. Our alloy is also particularly adaptable for makm drop forgings, of intricate desi where t e casting can be made of adii mite of larger size than the desired finished forging and the finishing can be completed in one set of dies and in one operation; in this way,

greatly reducing the cost of such forgings. Our product is "suitable for the reatest variety of uses. It ma be used or castings, both large and smal, where wear and resistance to heat are im ortant factors. It may also be used for too s, such as hammers, axes, picks, shovels, saws, andin fact, it is particularly adaptable for use generally on account of its dual nature of cast, iron and steel. The amount and expense of finishing can be greatly reduced for the reason that adamite will, in its primary or cast state, take the form of the article to be manufactured, requiring, in consequence, only a small amount of finishing in its secondary or worked state.

We claim-v 1. As a newarticle of manufacture, an

alloy comprising essentially silicon .10% to 2.00%; chromium .5% to 1.50%; nickel 25% to 1.00%; sulfur, not exceeding phosphorus, not exceeding .12%; manganese, not exceeding .45%, total carbon 1.25% to 3.50%; and iron approximately suflicient to complete the 100%.

2. As a new article of manufacture, an alloy comprising essentially the following elements in substantially the following roportions: silicon .70%, sulfur 033%, p osphorus 01%, manganese total carbon 1.88%, nickel 50%, chromium .90%, and iron approximately suflicient'to complete the 100%.

Si ned by the said JAMES RAMSEY SPEER at idland, Pa., this 11th day of March, A. .D. 1913, and by the said WILLIAM. L. Fons'mn, at Midland, Pa., this 11th day of March, A.'D. 1913.

JAMES RAMSEY SPEER. WILLIAM L. .FORSTER. Witnesses:

C. BROOKS, FRANK B. Fosran. 

